Apparatus for sizing and shaping ends of pipes

ABSTRACT

Apparatus for sizing and shaping the ends of large heavy duty pipes which are to be welded together is mounted on trolleys by which it is inserted into one of the pipes. An air driven hydraulic pump is operable to feed hydraulic fluid either to a single hydraulic actuator or to a circumferential array of hydraulic jacks. The single actuator has a movable actuator rod which carries a detachable support ring. An anchorage ring is secured detachably to the cylinder body of the single actuator. A plurality of angularly spaced forming blocks are coupled to the anchorage ring by suitable links and are engaged in T-shaped slots in the support ring, the slots being angled with respect to the axis of the actuator rod. The anchorage ring, support ring and array of forming blocks can be replaced by others of different size. In the other embodiment the hydraulic jacks, which each carry a forming block, are carried by a support frame which is mounted detachably on the pump. The support frame carrying the jacks can be replaced by another of different size.

United States Patent [1 1 Watson 1451 July 29, 1975 1 APPARATUS FOR SIZING AND SHAPING ENDS OF PIPES [75] Inventor: Geoffrey Walter Watson,- lnverness,

Scotland [22] Filed: July 23,1973

21 Appl.No.:38l,521

[30] Foreign Application Priority Data July 25, 1972 United Kingdom 35180/72 [52] US. Cl 72/393; 269/48.1 [51] Int. Cl B2ld 41/02 [58] Field of Search 72/393, 370, 392; 269/48.l; 29/255, 282

[56] References Cited UNITED STATES PATENTS 2,906,226 9/1959 Myrick ct al. 269/48.l 3,031,994 5/1962 Clark 269/48.l 3,044,431 7/1962 Cummings..... 269/48.l 3,109,477 11/1963 Avera ct a1. 269/48.1 3,229,972 1/1966 Cunningham.. 269/48.1 3,261,529 7/1966 Pagan 269/48.1 3,445,104 5/1969 Douglas 269/48.1 3,572,081 3/1971 Alexander... 72/393 3,684,149 8/1972 Ambler 269/48.1 3,741 ,457 6/1973 Gwin et a1. 269/48.l

3,770,927 11/1973 Christopher ..269/48.l

Primary Examiner-C. W. Lanham Assistant Examiner-James R. Duzan Attorney, Agent, or Firm-Stevens, Davis, Miller & Mosher 71 ABSTRACT Apparatus for sizing and shaping the ends of large heavy duty pipes which are to be welded together is mounted on trolleys by which it is inserted into one of the pipes. An air driven hydraulic pump is operable to feed hydraulic fluid either to a single hydraulic actuator or to a circumferential array of hydraulic jacks. The single actuator has a movable actuator rod which carries a detachable support ring. An anchorage ring is secured detachably to the cylinder body of the single actuator. A plurality of angularly spaced forming blocks are coupled to the anchorage ring by suitable links and are engaged in T-shaped slots in the support ring, the slots being angled with respect to the axis of the actuator rod. The anchorage ring, support ring and array of forming blocks can be replaced by others of different size. In the other embodiment the hydraulic jacks, which each carry a forming block, are carried by a support frame which is mounted detachably on the pump. The support frame carrying the jacks can be replaced by another of different size.

2 Claims, 13 Drawing Figures PATENTED JUL 2 9 I975 SHEET PATENTED JUL 2 91975 ll vwgwmm a PATENTED JUL29 I975 3, 8 9 6 6 55 PATENTE 3,896,655

SHEET 8 APPARATUS FOR SIZING AND SHAPING ENDS OF PIPES This invention relates to apparatus for sizing and shaping the adjacent ends of large heavy duty pipes so as to prepare the said ends of the pipes for welding coaxially to each other. The apparatus is of the kind which includes a circumferential array of movable forming blocks, means supporting the forming blocks and serving to guide movement of each forming block along a respective substantially radial path, and actuating means for moving each block along its respective path into and out of forming contact with the radially inner surface of the end part of a pipe to be shaped. the actuating means being operated by the action of fluid pressure to move the forming blocks along their respective paths. The radially outer surface of each forming block may be shaped to suit the desired shape of the inner surfaces of the end part of the pipe. For example the radially outer surface of each forming block may be arcuate.

The range of sizes of pipe which can be sized and shaped satisfactorily by a single piece of apparatus of the kind referred to above is limited and is governed by the range of effective operation of the combination of forming blocks and actuating means which together function as an expanding device. Attempts to enlarge the range of pipes which can be sized and shaped satisfactorily by a single piece of apparatus of the kind referred to have resulted in unstable mechanisms which are subject to wear or distortion and require excessive maintainance. Accordingly, in order to be able to size and shape a wide range of different pipe sizes, operators have been forced to stock a significant number of different pieces of apparatus of the kind referred to, each single piece apparatus being designed to size and shape pipes within a respective limited range of pipe sizes.

An object of this invention is to enable an operator to minimise the apparatus he must stock, and thus to minimise his capital outlay, whilst retaining a capability of sizing and shaping end portions of a large range of pipe sizes.

According to this invention there is provided apparatus for sizing and shaping the adjacent ends of large heavy duty pipes so as to prepare the said ends of the pipes for welding coaxially to each other, including a circumferential array of movable forming blocks, means supporting the forming blocks and serving to guide movement of each forming block along a respective substantially radial path, actuating means for moving each block along its repective path into and out of forming contact with the radially inner surfaces of the end parts of the pipes. the actuating means being operable by the action of fluid pressure to move the forming blocks along their respective paths, and a power plant which includes a pump for generating fluid pressure to operate said actuating means. the supporting and guiding means being secured detachably to said power plant.

lt will be appreciated that the power plant can be used in combination with a selected one of a range of sizes of supporting and guiding means, and thus can be used to size and shape a wider range of sizes of pipe than can a power plant which has supporting and guiding means fixed thereto. Each supporting and guiding means of the range which can be used with the power plant carries a respective number of movable forming blocks and is suitable for use in sizing and shaping a respective limited range of sizes of pipe within the wider range referred to above. Each forming block may carry a detachable shoe which defines its radially outer surface.

Preferably the pump is a liquid pressure generating pump which is arranged to generate liquid pressure for operating the actuating means.

Pipes having ends which are to be sized and shaped for welding to one another can be very long, for example, of the order of 40 feet in length. In order to size and shape adjacent ends of a pair of such long pipes which have been brought together end to end, the apparatus, which usually is mounted upon a trolley, is inserted into one of the pipes through the end thereof remote from the other pipe, is pushed along the length of said one pipe and is positioned in the region of the adjacent ends of the two pipes. If liquid pressure is fed to the actuating means from a source of liquid pressure outside the pipes, it will be appreciated that long high pressure hydraulic hoses lead from the apparatus along the length of said one pipe through the open end thereof to the source of liquid pressure. Such long high pressure hydraulic hoses are vulnerable to damage and leakage through a damaged portion of such a hose is difficult to detect. Furthermore such hoses are expensive and difficult to repair. A subsidiary object of this invention is to avoid the need to provide long lengths of high pressure hydraulic hose.

The pump may include a pneumatic motor which is operable to drive the pump by compressed gas supplied from an external source. Suitable hose for the conveyance of compressed air is relatively easily replaced, is relatively inexpensive, and the noise of air escaping through a damaged portion of such a hose draws the attention of the operator to the fact that damage has occurred.

In one embodiment of this invention, the actuating means comprise a piston and cylinder device which forms part of the power plant and. has a piston rod which projects through an end wall of the cylinder, the liquid pressure output from the pump being connected to a cylinder space of the piston and cylinder device, and the supporting and guiding means comprise an annular support block secured detachably to the piston rod outside the cylinder and anchorage means secured detachably to the cylinder, each forming block being connected to the anchorage means by a linkage and being arranged for sliding movement on a co-operating radially outer surface portion of the support block, each said surface portion being angled with respect to the axis of the piston rod, the arrangement being such that movement of the piston rod due to the action of fluid pressure fed to said cylinder space by the pump results in relative sliding movement between each forming block and the co-operating angled surface portion of the support block so that the forming blocks are moved radially outwardly.

Conveniently a directional valve controls the connection of the liquid pressure output of the pump to the cylinder spaces on each side of a piston of the piston and cylinder device. The piston and cylinder device may comprise two or more pistons on the piston rod, each piston being slidable within a respective cylinder.

ln another embodiment of this invention, the supporting and guiding means comprise a support frame which is secured detachably to the pump and which carries a circumferential array of hydraulic jacks which function as said actuating means, each jack having a movable actuating part which carries a respective one of the forming blocks and guides the respective forming block for radial movement, and conduit means releasably connected to each jack and arranged to convey fluid pressure from the pump output to the jacks to actuate said jacks.

The apparatus may include control means by which a selected number of the jacks can be operated independently of the other jacks so that different forces can be exerted on different sections of the portions of the ends of the pipes to be shaped and sized.

Two embodiments of this invention will be described now by way of example with reference to the accompanying drawings, of which FIG. I is a side view of part of two large heavy duty pipes in abutting end to end relationship, the adjacent end portions of the two pipes being broken away to show a rerounder unit which is positioned therein for sizing and shaping the adjacent ends of the pipes;

FIG. 2 is a longitudinal section of the power plant of the rerounder unit shown in FIG. 1;

FIG. 3 is a section on the line IIIIII of FIG. 2;

FIG. 4 is a section on the line IVIV of FIG. 2;

FIG. 5 is a section on the line VV of FIG. 1',

FIG. 6 is a partial end view as seen along arrow A in FIG. 1;

FIGS. 7A and 78 together constitute a partly sectioned elevation of the hydraulic actuator of the rerounder unit shown in FIG. I, the section being taken on the line VII-VII of FIG. 6;

FIGS. 8A, 8B and 8C respectively illustrate different examples of anchorage rings, support blocks, forming blocks and connecting links mounted in position upon the hydraulic actuator of FIGS. 7A and 7B;

FIG. 9 is a partly sectioned side elevation of another form of rerounder unit according to this invention, the trolley being omitted for convenience; and

FIG. 10 is an end view of FIG. 9.

Referring to FIG. I of the drawings, a rerounder unit 10 is mounted upon suitable trolleys I1 and is inserted into one of two large heavy duty pipes 12 and 13 which are in end to end abutment for sizing and shaping prior to being welded together to form a single pipe. The rerounder unit 10, which was inserted into the pipe 12 through the end thereof remote from the end of the pipe 12 which abuts the adjacent end of the other pipe 13, has one end aligned with the abutting ends of the two pipes 12 and I3 and the other end projecting from the open end of the pipe 12.

The rerounder unit 10 includes a power plant 14 comprising an air driven hydraulic pump (not shown in FIG. 1) and a hydraulic actuator 16. The hydraulic actuator I6 has an actuator rod 17 which projects axially therefrom away from the pump and carries a support block I8 which supports and guides a plurality of angularly spaced forming blocks 19 in a manner which will be described in more detail below. The end part of the rerounder unit 10 which projects outside the pipe 12 carries control apparatus 20 which will be described in more detail below.

Referring to FIGS. 2 to 5, conveniently the air driven hydraulic pump 15 is a reciprocating pump which has a double-acting piston air motor located in a central casing portion 21 and arranged to generate liquid pressure in whichsoever one of the end casing portions 22 and 23 towards which it is moved. It will be appreciated, however, that any other convenient and known form of air driven hydraulic pump, such as a rotary or reciprocating piston pump, may be used.

Compressed air is fed from a suitable external source (not shown) to an air inlet valve block 24, which is mounted on the end casing portion 23 remote from the hydraulic actuator I6. via a pipe 25 which extends through the outer casing of the rerounder unit 10 from the end thereof which projects from the pipe 12. The air inlet valve block 24 is connected by suitable conduits (not shown) within the pump casing to the air motor in the central casing portion 21.

A second valve block 26 mounted on the end casing portion 23 of the pump casing serves as the pump outlet, being in communication within the pump casing with the liquid pressure generating means at the two ends, and is connected via a pipe 27 to a pilot operated hydraulic directional valve 28 which is mounted on the central casing portion 21.

Two pilot air supply pipes 29 and 30 extend one on each side of the compressed air supply pipe 25 from the control apparatus 20 to the directional valve 28.

The control apparatus 20 has a manually operable detent valve 31 which controls the connection of the pilot air supply pipes 29 and 30. The detent valve 31 has a control lever 32 which can be moved by hand from a null position in a selected one of two opposite directions so as to connect the compressed air supply pipe 25 to the pilot air supply pipe 29 or to the pilot air supply pipe 30 as required. The control apparatus also has a pressure control device 33 for controlling the pressure of air supplied to the air inlet valve block 24 via the compressed air supply pipe 25.

The rerounder unit 10 includes a liquid reservoir 34 between the air driven pump 15 and the hydraulic actuator I6. The pump 15 is operable to draw liquid from the reservoir 34 via a pipe 35 (see FIG. 4) which includes a filter 36. FIG. 3 shows that the reservoir 34 also has a breather valve 37 which communicates with the space above the level of hydraulic fluid within the reservoir 34. A liquid return pipe (not shown) interconnects the directional valve 28 and the reservoir 34.

Referring now to FIGS. 7A and 7B,-the hydraulic actuator 16 comprises a piston 37 which is slidable in a cylinder 38 and which is fixed to the actuator rod 17 which extends through one end wall 39 of the cylinder 38. The cylinder spaces 40 and 41 on each side of the piston 37 are connected to the directional valves 28 via a respective one of two pipes 42 and 43 (see FIGS. 2 and 3). An anchorage ring 44 is secured detachably by set screws 45 to the outer radial face of the cylinder end wall 39 so as to be coaxial with the actuator rod 14. The annular support block 18 is carried detachably by the end of the actuator rod 14 outside the cylinder 38. The radially inner portion of the support block 18 is clamped against a shoulder which is defined by a washer 46, the washer 46 being held in position at the end of the actuator rod 17 by a nut 47 which is screwed onto the end of the actuator rod 17. The nut 47 is held against movement relative to the rod 17 by a locking key (not shown) which is engaged in an axially extending slot in the end of the actuator rod 17. A circumferential array of flat angled surfaces 48 are formed in the radially outer surface of the support block 18 (see FIG. 6). Each flat surface 48 is angled with respect to the axis of the piston 37. The angled surfaces 48 and the axis of the piston 37 converge towards the body of the cylinder 38. Each flat angled surface 48 has a T-shaped slot 49 defined therein, the longitudinal axis of each T- shaped slot 49 lying in a radial plane. Each of the circumferential array of forming blocks 19 is engaged within a respective T-shaped slot 49 for sliding movement along the respective T-shaped slot 49. Each forming block 19 is connected pivotally to one end of a respective link 50 which in turn is hinged to a respective fixed pivot 51 mounted on the anchorage ring 44.

In order to size and shape the adjacent ends of the pipes 12 and 13 so that they are prepared for welding together, the rerounder unit mounted upon the trol- Ieys 11 is inserted through the open end of the pipe 12 until the circumferential array of forming blocks 19 are located in the region of the abutting ends of the two pipes 12 and 13, as shown in FIG. 1.

Once the rerounder unit 10 is in position, the operator selects the required working air pressure by means of the pressure control device 33 and moves the handle 32 from the null position to the clamp position so that the appropriate one of the two pilot air supply pipes 29 and 30 is connected to the main compressed air supply pipe 25. The resultant pneumatic signal transmitted to the pilot operated directional hydraulic valve 28 actuates the valve 28 so that the second valve block 26 is connected to the pipe 43 and the pipe 42 is connected to the liquid return pipe. Thus the air driven pump 15 is operated by compressed air supplied to the air motor via the main compressed air supply pipe and the liquid pressure output from the pump 15 is conveyed via the second valve block 26, the pipe 27, the directional valve 28, and the pipe 43 to the cylinder space 41. The actuator rod 17 carries the support block 18 towards the body of the cylinder 38 due to the action of liquid pressure in the cylinder space 41. The interaction of the forming blocks 19 retained in respective T-shaped slots 49 and the linkage 50 connecting each forming block 19 to the anchorage ring 44 results in the forming blocks 19 moving outwardly along substantially radial paths into forming contact with the surrounding pipe end portions 12 and 13. The maximum forming pressure exerted by the forming blocks 19 is dependent upon the maximum liquid pressure which is built up in the cylinder space 41 and this is determined by the pressure of the main air supply selected by operation of the pressure control device 33. The air driven pump 15 is arranged so that it stalls when the liquid pressure it has generated balances the air pressure acting in the air motor. The generated liquid pressure is held when the pump 15 is stalled so that the applied forming pressure is maintained also. The pump 15 will operate automatically to compensate for liquid pressure losses so as to ensure that the working pressures are maintained. When forming pressure has been applied for a period sufficient to ensure that the pipe ends 12 and 13 have been suitably shaped and sized, and the pipe ends 12 and 13 have been welded together. the handle 32 of the detent valve 31 is moved by the operator from the clamp position to the unclamp position so that the other pilot air supply pipe 29 or 30 is connected to the main air supply pipe 25. Thus the directional valve 28 is actuated to connect the cylinder space to the liquid pressure output valve block 26 of the air operated hydraulic pump 15 and to connect the cylinder space 41 to the reservoir 34 so that the actuator rod 17 is moved in the other direction and the forming blocks 19 are moved inwardly along the substantially radial paths.

The anchorage ring 44, support block 18, and circumferential array of forming blocks 19 are selected from a range of anchorage rings, support blocks and forming blocks to suit the diameter of the pipe ends to be sized and shaped, and a representative selection are shown in FIGS. 8A, 8B and 8C.

Referring now to FIGS. 9 and 10, another form of rerounder unit 60 includes a power plant comprising an air driven hydraulic pump 61, which may be similar in construction and operation to that described above with reference to FIGS. 2 to 5 and which will not be described in detail herein, and a plurality of hydraulic jacks 62 which are carried by a circular support frame 63 which is mounted detachably upon the body of the air driven pump 61. The jacks 62 are mounted within the radially outer periphery of the support frame 63 and are spaced apart angularly with respect to one another so that their movable actuating parts 64 extend radially outwardly. Each movable actuating jack part 64 carries a respective forming block 65. Each hydraulic jack 62 has a quick disconnect coupling 66 for connection to a respective pipe 67 which is connected at its other end to the liquid pressure output of the air operated hydraulic pump 61. In operation of this embodiment of the invention, the circumferential array of forming blocks 65 are urged outwardly by operation of the respective hydraulic jacks 62 into forming contact with the surrounding pipe portions 68 and 69 to be shaped and sized. When the surrounding pipe portions 68 and 69 have been shaped and sized suitably, and welded together, the forming blocks 65 may be withdrawn radially inwardly by the respective jacks 62.

The support frame 63, and/or the circumferential array ofjacks 62 carried thereby may be selected from a range of such equipment to suit the diameter of the pipes to be shaped and sized. The apparatus may be arranged so that a selected number of the jacks 62 may be operated independently of the others so that different forces can be exerted on different sections of the portions of the ends of the pipes to be shaped and sized.

It will be appreciated that in either embodiment of the invention described above, the forming blocks may carry detachable shoes. The outer surface of each block or detachable shoe carried thereby, may be shaped to suit the desired shape of the respective pipe portions to be shaped and sized.

I claim:

1. Apparatus for sizing and shaping the adjacent ends of large heavy duty pipes so as to prepare said ends for welding coaxially to each other, comprising:

a circumferential array of movable forming blocks;

means supporting the forming blocks;

guide means serving to guide movement of each forming block along a respective substantially radial path; and

a power plant which includes a piston and cylinder device having a movable piston rod which projects through and is guided for rectilinear movement through an end wall of the cylinder for moving each of the blocks along its respective path and a fluid pressure pump for generating fluid pressure to operate said piston and cylinder device, said fluid pressure pump having a fluid pressure output which is connected to a cylinder space of the piston and cylinder device;

rectilinear movement of the rod due to the action of fluid pressure in said piston and cylinder device results in sliding movement between each forming block and the co-operating angled surface portion of the support block so that the forming blocks are moved radially.

2. Apparatus according to claim 1 including a directional valve for controlling the connection of the fluid l pressure output of the pump to the cylinder spaces on each side of a piston of the piston and cylinder device. 

1. Apparatus for sizing and shaping the adjacent ends of large heavy duty pipes so as to prepare said ends for welding coaxially to each other, comprising: a circumferential array of movable forming blocks; means supporting the forming blocks; guide means serving to guide movement of each forming block along a respective substantially radial path; and a power plant which includes a piston and cylinder device having a movable piston rod which projects through and is guided for rectilinear movement through an end wall of the cylinder for moving each of the blocks along its respective path and a fluid pressure pump for generating fluid pressure to operate said piston and cylinder device, said fluid pressure pump having a fluid pressure output which is connected to a cylinder space of the piston and cylinder device; said supporting and guide means being secured detachably to said power plant and including: an annular support block which is secured detachably to the piston rod outside the cylinder; and anchorage means secured detachably to the cylinder; each forming block being connected to the anchorage means by a linkage and being arranged for sliding movement on a cooperating radially outer surface portion of the support block which is angled with respect to the axis of the piston rod so that rectilinear movement of the rod due to the action of fluid pressure in said piston and cylinder device results in sliding movement between each forming block and the co-operating angled surface portion of the support block so that the forming blocks are moved radially.
 2. Apparatus according to claim 1 including a directional valve for controlling the connection of the fluid pressure output of the pump to the cylinder spaces on each side of a piston of the piston and cylinder device. 